﻿// Copyright 2004-2011 Castle Project - http://www.castleproject.org/
// 
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
// 
//     http://www.apache.org/licenses/LICENSE-2.0
// 
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

namespace Castle.MicroKernel.Lifestyle.Scoped
{
	using System;
	using System.Collections.Generic;
	using System.Linq;
	using System.Threading;

	using Castle.Core.Internal;

	public class ScopeCache : IScopeCache, IDisposable
	{
		// NOTE: does that need to be thread safe?
		private IDictionary<object, Burden> cache = new Dictionary<object, Burden>();

		public Burden this[object id]
		{
			set
			{
				try
				{
					cache.Add(id, value);
				}
				catch (NullReferenceException)
				{
					throw new ObjectDisposedException("Scope cache was already disposed. This is most likely a bug in the calling code.");
				}
			}
			get
			{
				try
				{
					Burden burden;
					cache.TryGetValue(id, out burden);
					return burden;
				}
				catch (NullReferenceException)
				{
					throw new ObjectDisposedException("Scope cache was already disposed. This is most likely a bug in the calling code.");
				}
			}
		}

		public void Dispose()
		{
			var localCache = Interlocked.Exchange(ref cache, null);
			if (localCache == null)
			{
				// that should never happen but Dispose in general is expected to be safe to call so... let's obey the rules
				return;
			}
			localCache.Values.Reverse().ForEach(b => b.Release());
		}
	}
}